RDMA/srpt: Remove unnecessary assertion in srpt_queue_response

Since ch has already been de-referenced by the time we get to the BUG_ON,
it is useless. The back trace alone is enough to tell what is going on,
delete the redundant BUG_ON.

Link: https://lore.kernel.org/r/20191217194437.25568-1-pakki001@umn.eduSigned-off-by: Aditya Pakki <pakki001@umn.edu>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/ulp/srpt/ib_srpt.c

@@ -2810,8 +2810,6 @@ static void srpt_queue_response(struct se_cmd *cmd)
 	int resp_len, ret, i;
 	u8 srp_tm_status;
 
-	BUG_ON(!ch);
-
 	state = ioctx->state;
 	switch (state) {
 	case SRPT_STATE_NEW: